Yes, most Americans do support legal abortion

A conservative-packed Supreme Court has overturned its own 1973 Roe v. Wade decision, which made access to legal abortion a constitutional right. This means an end to a federal guarantee of legal abortion and, instead, individual states would create their own laws surrounding whether or not to permit legal abortions. 

Since the 1990s, reported abortion rates in the U.S. have been on the decline, Statista found. A 2018 Reuters report found that both pro-abortion and anti-abortion activists believe that stricter laws surrounding abortion have caused abortion rates to decline in the U.S.